Ribociclib is a high-specificity cell cycle-dependent kinase (CDK4/6) inhibitor which is developed by the Novartis Company and is orally effective, and the code of ribociclib is LEE011. LEE011 is a dual inhibitor of CDK4/6, and can remarkably inhibit growth of 12 of 17 kinds of neurocytomas. The drug is in stage-III clinical test currently, and is used for treating an advanced breast cancer. Owing to successful research of the drug, another important choice will be provided for patients suffering from the metastatic breast cancer. Because the drug does not have a standard Chinese name, the applicant transliterates ribociclib into ‘Ruiboxi′ni’ herein.
The chemical name of ribociclib (I) is 7-cyclopentyl-N,N-dimethyl-2-{[5-(piperazine-1-yl)piperidine-2-yl]amino}-7H-pyrrole[2,3-d]pyrimindine-6-formamide, and the structural formula of ribociclib is as follows:

Literatures such as PCT patent WO2010020675 of the original research company and United States patent US20120115878 have reported a synthetic method of ribociclib, and preparation steps of the synthetic method comprise synthesis of intermediates A and B and a process of preparing ribociclib by condensation of the A and the B.

By analysis of the above synthetic routes, the intermediate A as a parent ring is prepared in a way that a trihalogenopyrimidine compound and cyclopentylamine are subjected to nucleophilic aromatic substitution reaction, Sonogashira reaction and cyclization reaction under an alkaline condition to obtain a hydroxyl compound of pyrimidine pyrrole, and the compound is then oxidized by manganese dioxide and subjected to a process including amidation reaction and the like in the presence of sodium cyanide to obtain the target intermediate A. Obviously, the preparation process is quite complicated, lots of unconventional reagents require to be used, and particularly, use of a noble metal catalyst and use of the sodium cyanide as a deadly poisonous compound bring great difficulties to industrial production.
For overcoming existing process defects, a preparation technology which is simple in process, economical and environmentally friendly, and high in quality is developed, and particularly, a process technology capable of adapting to industrial production needs to be sought, and is of great realistic significance on improvement of the economic and social benefits of the drug.